The ability of the innate immune system to recognize and respond to microbial components has been largely attributed to the family of TLRs. They are able to discriminate among distinct molecular patterns associated with microbial components. Recognition of microbial products by TLRs results in induction of innate immunity mechanisms as well in development of antigen-specific adaptive immune responses. Some of TLR ligands start to be used to enhance immune defence mechanisms in fighting infections or malignancies. On the contrary, others were shown to be involved in immunopathogenesis of autoimmune disorders such as SLE.